| 摘要 |
PURPOSE:To obtain a necessary temperature in the gas in a heat recovery section by providing a combustion catalyst layer on the upstream side of exhaust gas in an exhaust heat recovery section and supplying a fuel into the combustion exhaust gas from the upstream side to burn the fuel with the residual oxygen and heating the combustion exhaust gas to a high temperature. CONSTITUTION:The temperature of the raw material flowing through a reaction tube 4 which is provided at a radiation heat transfer section 3 is heated to about 800 deg.C due to the temperature in a furnace which has reached 1000 deg.C obtained by burning a gas fuel by means of the main burner 2 provided in a heating furnace 1. The combustion exhaust gas leaving the radiation heat transfer section 3 is led by natural draft to convection heat transfer sections 5 and 6. In order to cover the shortage in the retained colory in the exhaust gas required for recovery of the exhaust heat, an auxiliary fuel is supplied from an auxiliary fuel supply header 7 on the upstream side of the convection heat transfer sections 5 and 6 to pre-mix the auxiliary fuel with the exhaust gas, and then the auxiliary fuel is made to react with O2 gas that remains in the exhaust gas in the combustion catalyst layer 8 to heat uniformly the exhaust gas to 1200 deg.C with the heat produced by the said reaction.
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